Telephone-exchange system.



H. P. CLAUSEN.

TELEPHONE EXCHANGE SYSTEM. APPLICATION man FEB. 19. ms.

1,241,923. V Patented Oct. 2,1917.

)4 B 5: r5 2! C H ll Le I lq S/amre/ase //7 van for:

HENRY P. cLAUsEn, or noun-r'vnianon,NnwYoRK, ASSIGNOR'TO wns'rnnny ELECTRIC oomrnng-moonroaa'rnn, on NEW YORK, 1\ T. Y.,-A oorcronn'r on a 7 OF NEW YORK.

To all whom it may concern:

Be it knownth-at I, HENRY B. GLAUsEn aciti'zen'of the United States, residing at Mount Vernon, in-the county of. Westchesr' ter and State of New York,,have invented; certain -'new' and "useful Improvements-1n" Telephone-Exchange Systems, of which the ,;t'01lowing-' is a full, clear,qconcise, and exact 10 change systems, and more particularly to such systems of the centralenergytype.

Thei is how in the a ming, atelephone' exchange system comprising subscribers stations A andB terminating at a '40 centralfoffi'ce, and a cord circuit C-located Y Thisrinvention Will be description.

This invention relates to telephone -ex- The objectof'this'inventionis to provide improved signaling means for such systems;

In central oflices, conslderable time 1s" wasted by operators listening inon aicord c1rcuit-when only one superv sory signal is displayed, the-operator assumingthat a sub-' scriber is waiting, when the non-coincident occurrence of both supervisory signals is due to one of the parties to the connection restoring his receiver 1 to the switchhook.

more promptly than the other party;

'In accordance with this invention,- the usual link circuit having a'signaling device associated with-each end thereof -is pro-' vided ywith'. apparatusafor. causing the si- Inultaneous operation of the signaling" devices to 'El1I:-nl Sh dlSCOI1neCt signals, when both subscribers have restored 1 the r re ceiversito theswitchhooks. on v 1 i ,v I

fully understood from the following description and the ac 'companying jdrawmg, in which all apparatus is shown 1n1ts normalor unactuated condition;-'

thereat for interconnecting the a subscribers station. i

Subscriber wishing converse with subscriberF B; r'emoves'the receiver frornthe plug into. ithejack indicated by the line sig-" nal, E thereby j causing the operation "of" relay v1-1 and cutofi' relay over a circuit from battery through the winding ofrelay 11,

sleeve contacts of the answering plug and jack and the windingo'frcutofl' 'relay 13 to ground-l Cutoff re1ay'l3 in operating causes 1 rntn inonn nxcnnnenfs s'r Mj..11 v v 'I j speeiiication'of Letters l atent I i ApplicationfiledFebruary 19,1916, Seria11o.79,439 i line lamp 10"'to-=be entinguishedm .The

sertion of the answeringplug inthe jack also causes the operation of supervisory re-i lay 12 over a circuit from battery through" thewindingfof relay 11, ring contacts of the answering'plugancbjacl one side of the line, substation apparatus, the other side I answering plug and the winding i of supervisory {relay-12 to ground. The-operation of, preventing the lighting of supervisory lamp 124. c l --1 Theopera'tor then actuates listening key 15, connecting the operatorls telephone set across the i talking strands ofthe} cord circu-it," and asks the desired number of the" 'ofthe line, tip contacts of the .jack ,and'- I r i of-relay l2 opensthenormal contacttherei calling subscriber. Upon learning the de-fl sired number to be that offsubscriber v the operator inserts the callii'ig 'plug' into the [jack of Bs line, Lthereby oausin'g the operation{ of relay 16 and c'utoif relay 1 7 7 calling? plug and jack @and the, winding of slow release-relay 1'9','-la1np 18, nor-inal'contact over circuit from" battery through the winding 0f: relay 16, sleeve contacts of the v 8.0" cutofl? irelay- 17 to "grounclim-Theoperation of i relay 16 causes Y- thelighting of; supervisory lamp 18 i over" a circuit from batter-y p through the right-hand norml ;ccmaceofi of relay20 and contact of relay 16 to1gr ound.

The operator now restores the listening key Y 15 to itSIlOllXlfllPOSfltiOIl andactuatesrin-g ing key 2131 connecting a 1 sourcekof l ringing currentj22 to the calledsubscribers line to actuatethe call bell23. After ringing the called subscriber the operator restores the ringing key 21 toqits" normal'po'sitionj. In response-to the sounding of call bell; 28. due to the passage; of current therethrough',;subscriber B removes the receiver'gitroin'the switchhook, thereby causing: the operation ofsu-pervisory relay 20 over 'acircuit 'froni battery through the winding of relay 116;

1600 v one :sideof the line, substation: apparatus,

ring contacts of the calling -.plug and jack,

the other side of the line, tip contactsot the j ajck andcallingplug and'the winding},

ofrelay 20130 ground; Re1a "-2() ;1in operat ing to the operator thatsubscriber'jBhas 1 ing; efl a'ces supervisory signalf-18', indioat-;

answered. The operation of relay 2 0 a-l so'-f I causes: the operation offslo-w r'elease, relay 19; over a 1 circuit from battery throughi' con-F tact airwa 1 1; .xal'ternatecontact of r l y 12, winding of relay 19, alternate contact of relay 20, and contact of relay 16 to ground. Assume now that subscribers A and B completetheir' conversation and A restores his receiver to the switchhook first, relay 12 releases, thereby closing one break in the circuit through to supervisory lamp 14. The opening of the alternate contactof relay 12 opens the circuitthrough.thewind ing of slow-release relay 19, but owing to the structure of relay 1,9, the alternate, con-- causedjto light in synchronism upon the res-. toration of Bs receiver to the switchhook,

the circuit for both lamps being from battery through the contact of relay 11, normal contact of relay 12' where it. branches, one branch being through lamp 1 1, lefthand alternate contactof relay 19 to normal contact of relay 20 and the other branch being through the right hand alternate con tact of, relay 19 and the lamp 18 to normal contact of relay QO-and thence through contact ofrelay 16 to ground. If, howevenB restores, his receiver to the switchhook after A. and simultaneously with the falling oil? of relay 19,.both lamps will. be caused, to light in synchronism, but over different circuits from those justtraced. .The circuit through lampl4 may then be traced from battery through contact of relay 11, normal contact of relay l2, supervisory lamp 1,4; and left-hand normalcontact ofrelay 19 to ground, and the circuitthrough lamp 18 may then be-traced from battery through right-hand, normal contact ofrelay 19, supervisory lamp 18, normal contact of relay 20 andcontact of relay 16 to ground.v

The display of supervisory signals .14L'and 18 in synchronism indicates to the operator that both subscribers have completed their conversation andrestored their. receivers to the sw-itchhooks, whereupon the operator. will respond by withdrawing the answering andcalling plugs from the. jacks, thereby disconnecting the two subscribers.

From the above it will be seen that neither of the supervisory lamps will be caused to. light until relay l9 releases.

To prevent the passage of battery from oneend ,ofthe cord circuit to the other, condensers 24 and 25 are-included in the tip andring conductors of the cord circuit.

Intelephone exchange systems prior to thisv invention, 1 whenever two subscribers were: in. conversation over telephone lines interconnected at a central office, andone subscriber.v restored his receiver to, the switchhook more promptly than the other, oneof the supervisorylamps would be caused to light immediately upon the resv only one of the disconnect signals would be displayed. Statistics which have recently been compiled show that out of the total number of callsresponded to by the operators, from ten to, twenty-five per centjaare due to the non-coincident occurrence of the disconnectsignals. Therefore, it, will readily. be seenthat. by means of this inventioii,wl1ereby.'the supervisory signalsasso- 3O ciated with the answering and calling ends. of the cord circuit. are not lightedto give a disconnect signal until after the expiration of a predetermined period; of. time which; should; be sufficient, for both: subscribers to have restoredtheir receivers to the switchhook, the. timewastedby the op:

erators entering upon. a, cord. circuit when only one signal thereoffis displayed is avoided. I

What claimed is:

1. In a telephone systein,;telephone lines. terminating; at a. central. oflice,-.a link circuit thereatfor interconnecting saidilines, a supervisory signaling, device associated with eachendrof the link circuit, and a slow re? lease relay jointly. controlled from theconnected telephone linesto: cause the.simul taneous. operation. of the. signaling devices when the. receiver of: one ofthe connected-v telephone-lines .is restored. to the switchhook. within a predeterminedtimeafter; the other is. restored. I

2. In a. telephonesystem,.teleph0ne lines terminating ata. central office,.a link, circuit thereat for interconnecting. said: lines,'. a.- S117 pervisory signaling device associated with each end of the link-circuit, a.supervis0r relay associated. with each end of thelinfi circuit controlled. over the res-pective connected telephone lines, and means 'joint-ly controlled by and cooperating with the; supervisory relays to cause the. simultaneous operation, of the signaling devices. when 1 the receiver of oneof the connected. telephone. lines is restored to:the. switchhookwvithinza predetermined time after the other .is restored.

3. In a telephone system, telephone, lines terminatingat a central'ofiice,.a link.- circuit 120 thereatfor interconnecting said. lines, a supervisory: signaling device associated with each. end of,- the' link circuit, a supervisory relay associated withi each end; of the link circuit controlled. over the. respective'con- 12.5 nectedtelephone lines, and a slow, release relay jointly controlled'by andcooperating with the. supervisory relayslto cause the simultaneous operation; of the signaling Qde vices when. the receiver. of; one of the 0011- nected telephone linesis restored to the switchhook within-a predetermined time after the other is restored.

4. In a telephone system, telephone lines terminating at a central oflice, a link circuit thereat for interconnecting said lines, a supervisory signaling device associated with each end of the link circuit, means associated with each end of the link circuit controlled over the respective connected telephone lines, and means jointly controlled by and cooperating with the aforesaid means to cause the simultaneous operation of the signaling devices when the receiver of one of the connected telephone lines is restored to the switchhook within a predetermined time after the other is restored.

5. In a telephone system, telephone linespervisory signaling device associated witheach end of said link circuit, and switching means jointly controlled from each of the connected lines for delaying for a prede termined period the operation of one of the signaling devices upon the restoration to the Copies of this patent may be obtained for five cents each, by addressing the Commissioner of'latents,

switchhook of the receiver on one of the connected lines and for causing the simultaneous operation of the signaling devices when the receiver of the other connected line is restored to the switchhook within the predetermined period.

6. in a telephone system, telephone lines I with the supervisory relays for delaying for a predetermined period the operationof onesignaling device upon the opening of one line circuit, and for causlng the slmultaneous operation of both signahng devices when the other line circuit is opened within the predetermined period. r V

In Witness-whereof, I hereunto subscribe my name this 16th day of February A. D.,

HENRY P. O LAUSEN.

Washington D. G. 

